Aircraft



June'18, 1935. v H. H. PLATT 2,004,961

AIRCRAFT Original Filed April 1'7, 193]. 5 Sheets-Sheet 1 T as 4 L I 6040 P 4. 4

0 je9" a 30 0 28 I 4 1 px e J a? INVENTOR.

3 54". I HAVIL AIID F LATT ATTORNEY.

June 18, 1935.

H. H. FLAT-r 2,004,961

AIRCRAFT Original Filed April 17, 1931 5 Sheets-Sheet 2 INVENTOR. 53

HAVILAND H. PLATT June 18, 1935.-

H. H. PLATT AIRCRAFT Original Filed April 17, 1951 5 Sheets-Sheet 3INVENTOR.

HAV/LAND H PLATT W if ATTORNEY.

H. H. PLATT June 18, 1935.

AIRCRAFT Original Filed Aprill'l, 1931 Hovering Neutral Gmund 75513:

IN VEN TOR HAV/LAHDHPLATT June 18, 1935. H. H. PLATT 2,004,961

AIRCRAFT Original Filed April 17, 1931 5 Sheets-Sheet 5 jo i1 v Ascent vFansrbon 7111/ 6 m! Ahead mmvrox.

ATTORNEY.

rmi HAVILAND H PLA'rr Patented June 18, 1935 I a 1 I STATE OFFICEHaviland H. Flatt, New York, N. Y., assignor ,to

Frederick W. Wilkening, Philadelphia, Pa.

Application April 17 ,'193 1,Serial No'. 533,232

' Renewed September 13, 1932 Claims; (01. 244-11) My invention relatesto certain new and useporting structure intermediate said pair of rofulimprovements in aircraft of the general tors may be minimized, andwhereby greater type forming the subject matter of my applicastrengthand compactness maybe produced in tion Serial No. 243,522, filedDecember 30th, the rotor system.

'5 1927, which has eventuated into Patent No. For the purpose ofillustrating my inventioni 5' 1,795,501 dated March 10, 1931. t t haveshown in the accompanying drawings one My present invention relates tocontrolling form thereof which is at present preferred by means, andother featuresof construction in the me, since the same has been foundin practice ircraft forming the subject matter of myabove to givesatisfactory'and reliable results, although 0 identified application. Ir V T e aircraft forming the subject matter of my mentalities ofwhich myinvention consists can earlier application, comprises a fuselage, a pairbe various y arran ed and Organized ahd'that of axially aligned rotors,on opposite sides of y ve is 1101? lilhiliedio the p e the fuselage,adapted to be po er dri en o to rangement and organization of theinstrumenbe freely rotating at the will of the operator, talities ashereinshown and described. -15

eachof said rotors comprising a plurality of piv- Referring to tdrawings, in Which k otally mounted aerofoil blades, extending genereneee ct c di t like pa 7 orally transversely of the direction of travel ofF g 1 represents a s lev i n m the aircrafhand adapted to revolve in anorbit Wh di r m a i f n a raf m yi about the axis of the rotors, meansfor autoy t o 2O matically oscillating each of said a'erofoil blades, Fu 2 pr n a S on 0 1 l ne of, in succession, about its respective pivotduring F e each revolution of the rotors, said angular osgu 3 s a muchenlarged sectional v w cillations or deflections of the ,aerof oilblades O t cc c, Shown in Figure about theirrespective pivots beinconfined Fig r 4 i a se ion n lin 4 f Fi e 2; 25 within relatively smallangles, and means for Figure '5 is a front elevation of the manualvarying the magnitude of the oscillationsor the control mechanism;maximum angle of deflection of said aerofoil' "F gure 6 is a S de eevatio Oft e Sam pa blades and for varying the event of the oscillay i itions in the orbit of said aerofoil blades, both gu 7 represents a top pView of the 3 at the will of the operator. u same;

The object of my present invention is to pro- Figures 8, 9, 10, 1 1, 12and 13 represent varivide improved controlling means for said air ousdiagrammatic views of the relationbetween craft and to provide'otherfeatures of construc the manual control and the rotor, in six differenttion which will simplify and strengthen the conpe a v Conditions Of theh- 35 struction of the aircraft as a whole. 7 ures showing the craft inthe hovering; neutral;

With the above and other objects in view, ground t ti v rtic l nt; n n;which will appear more fully from the followfull speed ahead conditions;respectively, 7 ingdetailed description, my i on consists According tomy present invention I provide his to be understood that the variousins-tru- 10':

40 of a single manual control, for aircraft of this a fuselage Zllfwhichmay be of any suitable 40 type, including a controlfstick'the forwardform, such as indicated in the drawings, inand rearward deflection ofwhich will tend to cluding t e undercarriage c p s t deflect andelevate, respectively, the aircraft; pair of landing wheels 22,-carriedp e and the leftward and rightward defiectionof outer axle'extensions ofthe arms 23, which are which will act upon the two rotorsdifferentially, pivotally secured to the fuselage at any suit- 45thereby to bank the craft in either of said direcable point, as at 24.The stay rods 25 areipiv tions. 4 y I otally connected to the arms 23,near the outer My invention further consists of a simplified endsthereof and are pivotally connected at26 control, whereby the magnitudeor amplitude of to the fuselage a suitable distance behind the theoscillations of therotorblades, as well as the pivotal point 24, so asto afford the desired event of the oscillations, may be varied'withouttriangular bracing for rigidity in a direction the intervention ofgearing and other intricate parallel to the longitudinal center line ofthe mechanism, and whereby the pair of opposed fuselage. The verticalbrace rods 2'! are pivrotors may be. mounted nearer to the longitudi--otally secured to the arms 23 at 28 and ,are suitnal median line of thefuselage, so that the supably pivoted to the fuselage at 29. Suitablethe fuselage, along the pivot or vertical line '33, g

in any suitable manner.

Above the fuselage 20 the rotor shaft hats ing 34 is rigidly supportedupon suitable sup porting members and braces 35.'-Through the suitablysupported near the outer ends of the housing 34, by the ball bearings orother suitable bearings 31.

, To each of the two opposed outer projecting portions of the rotorshaft 34 a series of three (more or less) arm spiders 38 is rig'idlysecured, said "spiders having a number of blade supporting arms 39corresponding to' the. number of blades used in the particular rotorconstruction;said arms being. in alignment. with each other. To theouter ends of the. arms 39, corresponding aerofoil'blades 40 arepivotally secured, in a manner disclosed in my application hereinabovereferred to, so that said blades may be, oscillated upon said pivotalsupports.

Upon each of the opposite ends of the rotor shaft housing 34 astationary cylindrical sleeve 4| is provided, concentric with the rotorshaft 36, for supporting the eccentrics which deflect or oscillate therotor blades. The sleeves 4| may be formed integrally with the rotorshaft housing 34, or they maybe affixed thereto by flanges or bolts, asshown in the drawings, or

by any suitable means.

Upon each of the stationary sleeves 4|, an

inner eccentric sleeve 42 is'rotatably mounted;

the inner end of which is provided with a sheave-like annular-cablereceiving groove 43,

and the outer portion-of which is an eccentrically disposed cylinder 44,of suitable eccentricity.

Upon the eccentric cylinder 44 the outer eccentric sleeve 45 isrotatably mountedw-said outer eccentric sleeve also having a sheave-likeannular cable receiving groove or channel 46 at its inner end concentricwith respect to the eccentric 44 and having at its outer end theeccentrically formed cylinder 41'. I I

The principle of the two eccentrics 44 and 41, the latter carried by theformer, is the ,same as the principle of the double eccentrics disclosedin my application hereinabove identified. Thus, by fixing the inner andouter eccentrics with respect'to each other and thus revolving them inunison or together, the aggregate or effective eccentricity of said twoeccentrics is merely shifted or displaced angularly with respect to theaxis of the shaft 36, while'the-rotati'on of one eccentric with respectto the other increases or decreases, as the case may be, the resultant,or effective eccentricity of the double or composite eccentrics.

' An annular ring or eccentric strap 48 is mounted uponthe outereccentric 41, through any suitable hearing, such as the ball bearing 49.A series of eccentric rods50, corresponding to the series of blades 40,is pivotally secured to the ringer strap48, at a series ofcircumferentially equidistant points 5|, with their outer ends pivotedto the corresponding blades 40, at points 52, in advance of, or behindthe supporting pivot point 53 (with respect to the cross section of theblades) a suitable distance, so that the generally radial displacementof the eccentric rods 50, during each revolution of the rotors 54, willcause a corresponding deflection or oscillation of the blades 40 abouttheir supporting pivot points 52.

Auxiliary eccentric rods 55 may also be provided intermediate the pivots5|, and auxiliary blade pivots 56, in alignment with the pivots 52, sothat the deflecting forces of the eccentrics may be transmitted to theblades at an added point nearer to the center of the blades, therebyminimizing any tendency of the blades to twist housing 34 the rotorshaft. 36 extends;being.;

For the purpose of increasing the stability of the rotors and further toeliminate any tendency ofthe blades to twist, tensional braces 51, in

due to the deflecting forces.

braces 51 are preferably connected to the four corners of a frame 58,which surrounds the shaft 36,, so that the tension may be transmitted inav line through the. shaft without interfering With the Shaft. I I

.Within the rotor shaft housing 34, suitable gearing may be provided foroperatively connecting the rctorshaft 35 with a suitable driving shaft59; said gearing comprising the bevel gear 60 and the bevel pinion 6|.The driving shaft 59 is extended to any-suitable point within thefuselage or outside of the fuselage,and is operatively connected to theforce of motive power,

such as internal combustion engine or the like, which latter may belocated at any suitable point (not shown in the drawings). Any suitableclutch 62 may be operatively interposed between the rotor shaft 36 andthe driving means, such as the bevel gear 60, for the purpose ofpermitting: the free rotationof the rotors independently of the engine,if desired. Anysuitable clutch operating handle or means 63 may beprovided, extending into the fuselage, for permitting the operator, toengage and disengage the clutch at will.

' Within the cock-pit of the fuselage, located suitably with respect tothe pilots seat 64, I provide the control mechanism shown particularlyin Figures 5, .6 and 7. The control mechanism shown in Figures 5 and 6includes opposed pairs of axially aligned stationary bearings 65and 56rigidly and permanently mounted or affixed to the fuselage, with theiraxis extending transversely of the fuselage, suitably in advance of thepilots seat. Within the bearing 66 and within the bearing 65, similartubular'shafts 61 are rotatably mounted;-the outer ends of each of saidshafts extending through and clear of the fuselage and havingattachedthereto the" cor-, respondingrocker arms 68 on the outside ofthe fuselage.

Through each of the hollow tubular shafts 61, a corresponding innershaft 69 is extended, with its opposite ends projecting clear of theouter tubular shaft 61 and having therocker arms 10 mounted on theirouter ends.

The rudder bar yoke 1| is rotatably mounted upon the outer tubularshafts 61;having-opposed journal portions 12 surroundingand journalledupon said outer shafts 61. A control stick yoke 13 is similarly mounted,upon the outer shafts 61, having opposed journal portions M, whichsurround and are journalled upon said shafts 61 as shown particularly inFigures 5 and '7.

The control stick I5 is provided with a generally horizontal portion 16and a vertical or operating portion 11, generally at a right angle tothe lower portion 76. The lower horizontal end 76 of the stick I5extends horizontally through the center of the yoke 13 and isvjournalled therein, so that the stick may be oscillated transversely. Tothe inner journalled end of the stick 16, a differential lever 11 issecured, normally in a horizontal position, said differential leverhaving a pair of opposed spherical projections for knobs 78, whichextend into the bifurcated ends T9 of the outer difierentialfingers 80,secured to the outer tubular shafts 61, so that a transverse or sidewisedeflection of the control stick (5 will cause opposite rotations of thetwo outer tubular shafts 6i.

Through the center of the rudder bar yoke H, a rudder bar shaft 8! isjournalled, extending through said yoke in a generally uprightdirection. To theinner end-of the shaft Bl, the rudder bar difierentiallever 82 is secured, having a pair of opposed and generally sphericalprojections or knobs 83, which extend into and operatively engage thebifurcated ends of the opposed inner differential fingers 84, which aresecured to the two opposed inner shafts 69, respectively.

A suitable flexible shaft 92 may be extended from the shafts 8| to therudder shaft at the rear of the fuselage or to the shaft or pivot of anysuitable or conventional foot-operated treadle, or rudder bar 93, sothat a deflection of the foot-operated rudder bar will cause acorresponding rotation of theshaft 8i,,and thereby to cause adifferential variationin the event of a blade oscillation in the tworotors, so as to cause a banking of the craft.

To the control stick yoke l3, a notched or toothed sector 85 is secured,while to the rudder bar yoke H, a blade angle control handle 86 issecured, having a suitable detent 87 in juxtaposition to the teeth ofthe sector 85. A suitable amount of spring or resiliency is provided inthe blade angle control handle 86, so that the same may be deflectedaway from the sector 85 against the spring inherent in said arm to anextent sufiicient to disengage the detent 8'! from the teeth or notchesof the sector 85.

By changing the position of the handle with respect to the sector 85,angular relation of the inner and outer shafts 69 and! is varied, and soalso the angular relation of the rocker arms 10 and 68 is similarlyvaried.

From the two ends of the rocker arms 68, on each side of the fuselage,cables 88 extend around the sheave or cable groove 43 on the innereccentric sleeve 42, so that the deflection of the rocker arms 66 istransmitted to the inner eccentrics M.

From the outer ends of each of the rocker arms Ill, corresponding cables89 extend around the sheave or cable groove 45 of the outer eccentricsleeve 45, so that the deflections of the rocker arms 10 are translatedinto correspond.- ing angular or rotary displacementsof the outereccentrics 41. a

A suitable resilient take-up device, as for instance, a tension springor the like, may be I inserted in the slack side of the cable 8. so asto compensate or take up any slack in the cable due to theeccentricityofthe cable'groove or sheave 46. v i

a The rudder-like member 32 may be stationary or fixed or it may beoperated in the conventional manner by means of foot-operated treadlesor foot-operated rudder-bar 93, which may be connected through cables-90 on the two sides of the fuselage to cable arms 9| carried by therudder or rudder shaft. The foottreadles are not shown in detail in thedrawings, but are merely indicatedin end-view in Figure 1 of thedrawings, as these are merely conventional foot type of rudder bar.

The flexible shaft 92 may be extended from the shaft 8! directly to theshaft or pivot of the rudder-bar 93, or it may be extended to the shaft.of the rudder-like member 32, if the latter is pivotally 'mounted, andthrough this flexible shaft the deflection of the rudder bar 93automatically deflects the differential rotor control lever 82.v This inturn differentially afiects the inner control shafts 69. and hence theouter eccentrics 41;thereby advancing one eccentric and retarding theother eccentric, so as to increase the lift on one rotor and decreasethe lifton the other rotor and thereby bank the craft.

Lateral control of the ship on the other hand is obtained through thetransverse maneuver of the control stick-|5, while longitudinal andvertical control of the ship is obtained through the longitudinalmaneuver of the stick 15.

I am aware that the invention may be embodied in other specific formswithout departing from the spirit or essential attributes thereof, and Itherefore desire the present embodiments to be considered in allrespects as illustrative and not restrictive, reference being had to theappended claims rather than to the fore-- going description to indicatethe scope of the invention.

Having thus'described myinvention, what I hereby claim as new and desireto secure by Letters Patent, is:

1. Aircraft comprising a fuselage, a pair of rotors, each of said rotorscomprising aplurality of pivotally mounted aerofoil blades, ex-' tendinggenerally transversely of the normal direction of travel of the aircraftand adapted to revolve in an orbit about the axis of the rotors, meansfor automatically oscillating each of said aerofoil blades, insuccession, about its respective pivot during each revolution of therotors, said angular oscillations or deflections of the aerofoil bladesabout their respective,

pivots being confined between angles substan-' tially less than 360degrees, means for varying the amplitude of said angular bladeoscillations,

means for varying the event of said oscillations in the orbit of saidaerofoil blades, and a universally deflectable control stick in thefuselage, operatively connected to said amplitude and event varyingmeans, which stick, when,

deflected in the longitudinal median plane of the craft, acts equallyupon the two rotors to vary the event of the blade oscillations thereof,

and which stick when deflected transversely of the aircraft, actsdiiferentially upon the rotors,

diiferentially tovary the event of the oscillations thereof.

2. An aircraft comprising a fuselage, a pair of rotors, each of saidrotors comprising a plurality of pivotally mounted aerofoil blades,extending generally transversely of the normal direction of travel ofthe aircraft and adapted to revolve in a orbit about the axis of therotors, means for automatically oscillating each of said aerofoilblades, in succession, about its respective pivot during each revolutionof the rotors, said angular oscillations or deflections of the aerofoilblades about their respective pivots being confined between anglessubstantially less than 360 degrees, means for varying the amplitude ofsaid angular blade oscillations, means for varying the event of saidoscillations in the orbit of said aerofoil blades, a rudder forinfluencing the lateral direction of the craft, and a single manuallyoperable controlstick in the fuselage, operatively connected to saidamplitude and event varying means and said rudder, adapted to bedeflected in a plane parallel to the longitudinal vertical median planeof the craft, to equally vary the event of the blade oscillations ofboth rotors, and adapted to be deflected transversely of the aircraft,differentially to vary the event of .the oscillations of the two rotors,thereby to bank the craft, and simultaneously to deflect the rudder inthe corresponding direction and to acorresponding extent.

3. Aircraft comprising a fuselage,- a rotor comprising a plurality ofpivotally mounted aerofoil blades extending generally transversely ofthe normal direction of travel of the aircraft and adapted to revolve inan orbit about the axis of the rotor, means forautoinaticallyoscillating each of said aerofoil blades, in succession,

about its respective pivot during each revolution of the rotor, saidangular oscillations or deflections-of the aerofoil blades about theirrespective pivots being confined between angles substantially less than380 degrees means for varying the amplitude of said angular bladeoscillations, means for varying the event of said oscillations in theorbit of said aerofoil blades, and a universally deflectable controlmember in the fuselage, operatively connected to said amplitude andevent varying means.

4. An aircraft comprising a fuselage, a pair of rotors, each of saidrotors comprising a plurality of pivotally mounted aerofoil blades,extending generally transversely of the normal direction of travel ofthe aircraft and adapted to revolve in an orbit about the axis of therotors, means for automatically oscillating each of said aerofoilblades,in succession, about its respective pivot during each revolutionof the rotors, said angular oscillations or deflections of the aerofoilblades about their respective pivots being confined between anglessubstantially less than 360 degrees, means for varying the amplitude ofsaid angular blade oscillations, means for varying the event of saidoscillations in the orbit of said aerofoil blades, a rudder forinfluencing the lateral direction of the craft, and single manuallyoperable control means in the fuselage, operatively connected to saidamplitude and event varying means and said rudder, adapted to bedeflected in a plane parallel to the longitudinal vertical median planeof the craft, equally to vary the event of the blade oscillations ofboth rotors, and adapted to be deflected transversely of the aircraft,differentially to vary the event of the oscillations of the two rotors,thereby to bank .the craft and simultaneously to deflect the rudder inthe corresponding direction and to a corresponding extent. i

5. An aircraft comprising a fuselage, a pair of rotors, each of saidrotors comprising a plurality of pivotally mounted aerofoil'blades: ex-

tending generally transversely of the normal dimeans for automaticallyoscillatingv each of the blades in succession during each revolution ofthe respective rotors, about their respective pivots, between twopredetermined limiting angles, means for positioning'the two limits ofangularblade oscillation, at any desired part of the orbit of the bladesat the will of the operator, means for varying the angle between the twolimits of blade oscillation, also at the will of the operator, a" rudderfor influencing the lateral direction of the craft, and manuallyoperable control means in the fuselage operatively connected to saidfirst-named two'means and said rudder for controlling the same indefinite relation to each other.

'6. An aircraft comprising a fuselage, a pair of rotors, each ofsaidrotors comprising a plurality of pivotally mounted aerofoil bladesextending generally transversely of the normal direction of travel ofthe aircraft, and adapted to revolve in an orbit about an axis generallyabove the center of gravity of the fuselage,

means for automatically oscillating each'of said angular bladeoscillation, at any desired part of the orbit of the blades at the willof the operator, means for varying theangle between the two limits ofblade oscillation, also at the will of the operator, a rudder forinfluencing the lateral direction of the craft, and manually operablecontrol means in the fuselageoperatively connected to said first-namedtwo means and said rudder for controlling the same in definite relationto each other, a source of power carried by the fuselage operativelyconnected with said rotors, rotatably to propel the same with'theleading sides thereof travelling generally up- Wardly. f H

'7. In an aircraft, a fuselage, a pair of rotors each including aplurality of aerofoil blades, said rotors being adapted to revolvegenerally about an axis extending transversely of the direction oftravel, of the aircraft, automatic means for aiigula'rly oscillatingeach of the blades of each of the rotors, in succession as said bladespass through each revolution of their respective rotors, saidoscillations being confined between two predetermined opposed limits,means for varying the positions of the two opposed limits of angularblade deflection, and hence, to vary the event of the blade oscillationsin the orbit of the blades, means for varying the angle between the twolimits of angular blade deflection in each of said rotors, a rudder forinfluencing the lateral direction of the craft, and manually olpe'rablecontrol means in the fuselage, operatively connected to the means forvarying the event of the blade oscillations in each of the rotors andtosaid rudder, thereby to operate the eventcontrolling means in each ofthe rotors and said rudder in relation to each other. i

8. An aircraft comprising a fuselage, a pair of rotors, each of saidrotors comprising a plu-' to revolve in an orbit about the axis of therotors, means for automatically oscillating each of said aerofoilblades, in succession, about its respective pivot during each revolutionof the rotors, said angular oscillations or deflections of the aerofoilblades about their respective pivots being confined between anglessubstantially less than 360 degrees, means for varying the amplitude ofsaid angular blade oscillations, means for varying the event of saidoscillations in the orbit of said aerofoil blades, a rudder-like memberfor laterally influencing the craft, and manually operable control meansin the fuselage, operatively connected to said amplitude and eventvarying means, adapted to be deflected in a plane parallel to thelongitudinal vertical median plane of the craft, equally to vary theevent of the blade oscillations of both rotors, and adapted to bedeflected transversely of the aircraft, differentially to vary the eventof the oscillations of the two rotors.

9. An aircraft comprising a fuselage, a pair of coaxially disposedrotors having their axes generally above the center of gravity of thefuselage, and extending generally transversely of the normal directionof travel of the aircraft, each of said rotors including a plurality ofpivotally mounted cambered aerofoil blades spaced generally uniformlyfrom the axis thereof and having their respective pivotal axesintermediate their respective leading and trailing edges, a source ofpower adapted rotatively to propel said rotors with the leading side ofthe rotors traveling upwardly, variable means for oscillating each ofsaid aerofoil blades in sucoscillations either uniformly ordifferentially in p v said two rotors, at the will of the operator,comprising a pair of similar and opposite rotatable shafts each adaptedto vary the magnitude of the bladeoscillation of one of the rotors,respectively, and another pair of similar and 0pposite rotatable shaftseach adapted to vary the event of the blade oscillation of one of thesaid two rotors, respectively, and a variable coupling between saidfirst pair of shafts and a variable coupling between said second pair ofshafts, each capable of independent rotational motion about an axisdisposed transversely of the axes of said shafts and also capable ofbeing swung about the axes of said shafts, and handle means for rotatingsaid variable couplers about their axes, respectively, or about the axesof such shafts, at the will of the operator.

I-IAVILAND H. PLATT.

